In early days, a large quantity of wet Ammonium Uranyl Tricarbonate (AUT) slurry was produced from the phosphoric acid plant in the Institute of Nuclear Energy Research (INER), Taiwan. Initially, the AUT slurry was packed in PVC tanks.
After storage for a long time, the aged PVC tanks were likely to deteriorate and break and any leakage of AUT would result in an environmental contamination. Hence, the AUT slurry was subjected to a batchwise calcination treatment and packed in new containers. The dried AUT powder or agglomerate owns diverse particle size and shape as well as the uranium content and in both physical property and chemical composition AUT are heterogeneous. The 55-gallon drum is the new container and after AUT packing, the weight of each drum is several hundred kilograms.
According to the agreements between Taiwan and the International Atomic Energy Agency (IAEA), the category and account of nuclear materials owned by a state must be well established. It is necessary to determine the exact quantity of uranium in AUT stock by sampling and reliable analytical method. However, a representative sample is not easily obtained due to the heterogeneous property of AUT unless a facility for AUT homogenization treatment by milling and blending is established. Furthermore, operation cost and facility investment are high for such an AUT homogenization system. In order to obtain an AUT sample well recognized by INER and IAEA, an invention of sampling method and facility with limited investment is developed. The uranium content of AUT is determined and the analytical results are well accepted by both organizations.
In addition to AUT, this technology can also provide an effective method for sampling of the heterogeneous solid materials, either powder or agglomerate, used in agricultural and industrial areas.